feat(unstable): `--unstable-detect-cjs` for respecting explicit `"type": "commonjs"` (#26149)

When using the `--unstable-detect-cjs` flag or adding `"unstable":
["detect-cjs"]` to a deno.json, it will make a JS file CJS if the
closest package.json contains `"type": "commonjs"` and the file is not
an ESM module (no TLA, no `import.meta`, no `import`/`export`).

1 files changed, 3 insertions, 0 deletions

diff --git a/tests/specs/compile/detect_cjs/main.js b/tests/specs/compile/detect_cjs/main.js
new file mode 100644
index 000000000..8c55f673b
--- /dev/null
+++ b/tests/specs/compile/detect_cjs/main.js
@@ -0,0 +1,3 @@
+import { add } from "./add.js";
+
+console.log(add(1, 2));